The Ford Barn - View Single Post - Any particular antifreeze for a 221 flathead

40 Deluxe · 11-26-2016, 02:14 AM

Absolutely will work great. Green is the closest to the original permanent antifreeze back in the day, which gradually replaced alcohol (methanol) based antifreeze. It was called "permanent" because it did not evaporate ('boil') out of the cooling system like methanol, which meant topping off the radiator was a regular chore. Methanol boils at somewhere around 170-180* if I remember. So you changed to 'winter' thermostats (160*) in the fall so the methanol didn't disappear so quickly. Then went back to 180* in the summer. With "permanent" antifreeze you could leave the 180* stats in and get more warmth from the heater.

11-26-2016, 02:14 AM	#2
40 Deluxe Senior Member Join Date: May 2010 Location: now Kuna, Idaho Posts: 3,835	Re: Any particular antifreeze for a 221 flathead Absolutely will work great. Green is the closest to the original permanent antifreeze back in the day, which gradually replaced alcohol (methanol) based antifreeze. It was called "permanent" because it did not evaporate ('boil') out of the cooling system like methanol, which meant topping off the radiator was a regular chore. Methanol boils at somewhere around 170-180* if I remember. So you changed to 'winter' thermostats (160) in the fall so the methanol didn't disappear so quickly. Then went back to 180 in the summer. With "permanent" antifreeze you could leave the 180* stats in and get more warmth from the heater.